This item will be shipped within One Week Returns Subject to 15% restocking Fee FHBR204-20mm Rubber Interliner Ball Bearing Set Screw Locking 20mm Inner Diameter FHBR204-20mm conductive Rubber Interliner Ball Bearing, it uses to dissipate static, it reduces noise ans vibration, FHBR204-20mm commonly assembled in pressed steel housings, bearing is narrow inner ring, Standard seal is RST tight riding, full cover, and metal shroud seals.